Printing plate and process of making the same



June 30, 1936. B. J. LEWIS PRINTING PLATE AND PROCESS OF MAKING THE SAME Filed JuneBO, 1935 2 Sheets-Sheet l [730%72207 Wizard J Lezdz'y June 30, 1936. y B. J. LEWIS PLATE AND PROCESS OF MAKING THE SAME 2 Sheets-Sheet 2 PRINTING Filed June 30,. 1955 X f7zajarzfif" w I fmvzmzgdd LZWJ Patented June 30, 1936 PRINTING rLA'raANn raocsss or MAKING 'rns SAME Barnard J. Lewis, Brookline, Mass. Application June 30, 1983, Serial No. 878,391. 14 Claims. (01. 101-401J.)

This invention relates to the art of printing. and pertains more particularly to methods of producing a'plate for color printing, and to the resulting product. This application represents a i5 further development of the inventions disclosed in my Patent No. 1,980,069,dated November 6,

1934, and covers a specific improvement in the methods and articles therein broadly claimed.

In said application I have described several 10 methods of so preparing a printing plate for color printing that unique and unusual color shadings, tonal gradations, brush marks and other effects characteristic of handwork may be mechanically reproduced in a water color print by ordinary 15 letter press or intaglio printing methods. These results were obtained by coating the printing surface of a base member (or selected areas thereof) with a lacquer or other resinousmedium, and then forming irregularities or level variations in 20 the printing surface of the coated base by superposing additional increments of the medium or removing portions of the initial application to produce hills and valleys of sloping or uneven contours. 25 I have since discovered that my original process may be simplified and practiced to better advantage by utilizing (in the initial treatment of the base member) a sheet type of coating medium of the general character contemplated in my said application, but not specifically described therein; and I have discovered that the improved sheet material lends itself to special treatments which more clearly simulate the brush marks and other technical features which characterize a- 3 hand colored painting, and which effect economies in printing plates generally. The initial sheet coating may also be used in conjunction with the lacquer treatment above mentioned, and is particularly receptive to the transfer of the outlined image from a key plate or by direct photography.

I have also devised a unique form of metal base member which is especially suitable for application of the improved coating medium and which, of itself, constitutes (when desired) an irregular printing surface peculiarly adapted to produce unusual crayon effects in a water color print.

These, and other, specific purposes of the 50 present invention will be evident from the following description of my improved process in connection with recommended embodiments illustrated in the accompanying drawings; and will be pointed out in the appended claims. 55 In the drawings, which indicate with more or less exaggeration in detail several optional treatments of the improved plate,

Fig. l is a plan view of one form of printing plate constructed in accordance with this invention;

Figs. 2 and 3 are fragmentary views of the smooth and rough sides, respectively, oi the sheet coating material;

Figs. 4, and 6 are fragmentary sections taken on lines 4-4, 5-5 and 6-8 respectively, of Fig.1 illustrating optional treatments of the coating;

Fig. 7 is an enlarged section of a portion of Fig. 4, showing another treatment of the surface;

Fig. 8 is a section on line 8-8 of Fig. 1;

Fig. 9 is ajragmentary perspective indicating the mode of removing a portion of the sheet coatn Figs..10 and 11 are sectional views of another modification, showing the application of the brushing medium to the base member of Fig. 1, and to an ordinary electrotype, respectively; and

Figs. 12 and 13 are plan and sectional views respectively oi a further modification in the treatment of the printing surface. b

' In the particular embodiments chosen for the purpose of illustration in Figs. 1 to 8, the improved printing plate comprises a base member ii of suitably rigid material; a sheet coating i2 of a hard-drying and durable composition which is soluble by a suitable reagent and becomes plastic and'adhesive when softened or wetted by the solvent; and superposed deposits i3 01" a viscous and hard-drying coating medium having adhesive affinity for the base i I as well as for the sheet coating I2. When combined and treated in accordance with my process, these materials constitute a printing plate adapted for use in any press employed for letter press or intaglio printing, and having an irregular printing surface capable of receiving and retaining water color 40 inks and depositing the colors upon paper, according to well known printing practice.

In certain aspects of this invention, the base member may consist of a sheet of metal or fibre board or a block of wood, but I prefer to use the metal plate ll which has a rough or pitted surface H on one side. This pitted surface not only aflordsa fine bond for the superposed sheet I 2, but also (in whole or in part) constitutes, of itself, an irregular printing surface which is adapted to produce a desirable crayon effect in a color print and which is receptive to treatment with the viscous or brushing'medium l3, as indicated in Fig. 10. I

For the sheet coating I2, I prefer to employ a key plate, or which may be sensitized to take a photographic image.

The sheet is preferably smooth on one side as indicated at I! and irregular or pitted on its opposite side It. The latter may be formed by molding the sheet with sand paper applied to one side or by impressing any plate or textured surface thereon. Either side of the sheet may be applied to the metal base II, as elected, the smooth side representing full tone values when used asthe outer or printing surface, and the rough side producing semi-tone or crayon values in the resulting print. Lighter tonal values may be obtained by scratching or rubbing the pitted surface with suitable implements or materials to remove some of the small projections, or by other means; and darker tones may be produced by filling in the crevices with the lacquer or brushing compound. Either side of the sheet may also be treated by the solvent or with the brushing medium l3, according to my process.

Before applying the sheet, the pitted surface ll of the base member is thoroughly covered with the acetone solvent. The sheet coating 12 is then laid on the wetted surface, smoothed out to avoid wrinkles, and pressed down firmly, adhesively to unite the two parts. As soon as the bond is secure, the outline of the subject may be ap- Y making inclined incisions with a sharp knife which should be pressed through to the metal base. Portions outlined in this manner may be quickly removed by lifting one edge and peeling.

off the loosened strip, as indicated in Fig. 9. The edges of the remaining sections should be treated with the brushing medium I! (Figs. 4 and 5) to close any cracks against the admission of air or moisture and to cement the sloping margins to the base member. Any small excesses of the pyroxylin may be removed by acetone; and any portions accidentally cut away may be replaced and secured by means of the solvent supplemented by the lacquer medium if desired, or the spots may be filled in by applying the medium I! a one.

After the pyroxylin sheet has been cut (and patched if necessary) in this manner, its printing surface may be treated with the brushing medium or in any of the modes described in my former application. In accordance with the present invention, it is also subject to special treatment through the use of the acetone solvent which is preferably applied with a brush or otherwise to soften and deform the printing surface or to render it sufilciently plastic for further manipulation to produce fluctuating level variations, brush marks, textures or other irregular surface characteristics, each capable of producing unique and distinctive effects in the color prints impressed thereby. The number and variety of the attractive and pleasing results attained "by such optional treatments depend only upon the skill, experience, and artistic ability of the manipulator; and the value of my invention'resides more in its capacity for variation in practice and its adaptability to artistic manipulation than in any particular treatment which I might recommend.

To illustrate a few of the possibilities: the use of a stiff brush wet with acetone upon the dry sheet will produce distinct and sharp brush marks or scratchy lines I! (Fig. 6) in the print;

the application of light brush strokes I8 (Fig. 6)

or brush tamping IOiFig. '7') upon a part of the surface softened by the solvent will give more subdued lines or speckles; a vignette effect is obtained by moistening the sloping margins 20 of the sheet and then wiping them with a soft brush, with a cloth or with the finger; unusual wash effects are produced when the softened coating is tamped with a cork stopper or other porous and yielding substance which may be applied with varying pressure and may be twisted or tilted as desired; compressed air blasts upon the moistened surface'also produce wash effects which may be varied by directing the air stream at different angles; and specific textures may be imparted by impressing fabrics, leather, or the Any of the aforesaid treatments may be used.

in conjunction with each other and may be supplemented or varied by the use of the lacquer or other viscous medium which may be brushed, dropped, sprayed or otherwise deposited at selected points or areas of the printing surface; and these deposits may be varied still further, in kind or in degree, by additional increments or by removal of portions. The brushing medium may also be applied directly to the pitted surface of the base plate (Fig. 10) which may then be empioyed as a printing surface to give a crayon effect in the color print; and when the lacquer is applied in this manner or to other printing surfaces, a similar result is achieved by dusting or sprinkling grains 2| of pyroxylin or grains of other substances onto the soft medium (Figs. 12 and 13)..

So, too, this medium may be usedto fill the crevices or the etched or routed spots in an ordinary half tone, line or other printing plate (Fig. 11) thereby imparting fluctuating and/or full tone values to the coated or filled-in areas; and, when applied as a thin film, the lacquer will enable any metal printing plate to hold water color inks for printing purposes. Without such treatment a fiat surfaced metal plate does not have sumcient aillnlty for water color inks to give satisfactory results. This inherent incapacity of the ordinary fiat metal plate is remedied by applying the coating thereto; and, so far as I am aware, my printing plates are unique in solving the problem of mechanical reproduction of water colors by letter press printing.

It will be understood that an individual plate is prepared for each impression of the color to be printed, and that the order of printing the colors will depend upon the efiects to be achieved as determined by previous experience. The impression is made by any common type of letter press or intaglio press, and either characteristic may be selectively obtained by manipulation of the quantity of ink and the pressure upon the paper. If

aomeoe 3 the ink and pressure are light, the hills or higher levels of the printing surface are emphasized in the'prin't and the ink in the valleys is not transferred; iwhereas, under heavy -pressure the ink which fills the valleys or depressions of the irregular surface is transferred to the paper by suction to give the well known intaglio charac-'- teristics. In any case, the soft, flat colors, brush marks, tonal shadings and other features of a hand painted water color are recognizable in a print from a plate prepared according to the process herein described.

Plates thus prepared may also be used as molds for making metal electrotypes having corresponding irregular printing surfaces, and the latter may be curved for use in a cylindrical press. A thin lacquer coating may be applied to assist in holding the water color inks, but it will usually be found that the water color inks are trapped in the irregularities of the uncoated metal surface sufficiently to retain and properly transfer the colors to paper. My base members or electrotypes may be repeatedly used for differing subjects, for the coatings may be removed with the acetone solvent, thus effecting a substantial saving in the cost of manufacture of new plates.

It will also be evident that the pyroxylin sheet possesses marked advantages over metal or rubber which have heretofore been employed as a printing surface; and that, in this aspect of my invention. the utility and benefits of this sheet are not confined to color printing. When mounted upon any suitably rigid backer or base member, either flat or curved, the pyroxylin may be cut, trimmed, routed or otherwise manipulated with substantial savings in the cost of preparing metal or rubber plates; the sheet is initially less expensive than the ordinary materials used for this purposeand it may be removed, patched and reused repeatedly if desired.

I claim:

1. A method of making a printing plate, consisting in adhesively uniting a coating of soluble sheet material to a base plate, softening the exposed side of the plate with a solvent and forming depressions in the softened areas. and applying a brushable, hard-drying medium to other areas thereof, thereby to produce in the printing surface of the plate irregularities capable of forming corresponding tonal variations in a print taken from said surface by impression of the plate. I

2. A method of making a printing plate, consisting in attaching a sheet of pyroxylin material to a base member and applying local coatings of a brushable, hard-dryingmedium to selected areas of the sheet, thereby to form surface irregularities capable of producing corresponding tonal variations in a print impressed by said plate.

3. A method of making a printing plate, consisting in cementing a sheet of pyroxylin material to a base member, forming an image on 'the surface of the sheet, cutting and peeling away portions of the sheet and treating remaining portions of the sheet to form surface irregularities capable of producing corresponding tonal variations in a print impressed by said plate, said treatment including softening the sheet surface with acetone and deforming the softened areas to produce depressions in the printing surface.

4. A method of making a printing plate, consisting in cementing a sheet of pyroxylin material to a base member, forming an image on the surface of the sheet, cutting and peeling away portions of the sheet and treating remaining portions of the sheet to form surface irregularities capable of producing corresponding tonal variations in a print impressed by said plate, said treatment consisting in applying a brushable, hard-drying medium to the sheet to produce hills on the printing surface and varying the contours of said hills.

5. A method of making a printing plate. consisting in cementing a sheet of pyroxylin material to a base member, forming an image on the surface of the sheet, cutting and peeling away portions of the sheet and treating remaining portions of the sheet to form surface irregularities capable of producing corresponding tonai variations in a print impressed by said plate, said treatment including brushing the sheet surface 1 A with acetone.

6. A method of making a printing plate, consisting in cementing a sheet of pyroxylin material to a base member, cutting and peeling away portions of the sheet and treating remaining portions of the sheet to form surface irregularities capable of producing corresponding tonal variations in a print impressed by said plate, said treatment including tamping the softened sheet surface.

7. A method of making a printing plate, consisting in cementing a sheet of pyroxylin material to a base member, cutting and peeling away portions of the sheet and treating remaining portions of the sheet to form surface irregularities capable of producing correspondingtonal variations in a print impressed'by said plate, said treatment including molding impressions in the softened sheet surface. 8. A method of making a printing plate, consisting in cementing a sheet of pyroxylin material to a metal base member, cutting and peeling away portions of, the sheet, and applying a lacquer medium to the edges of the remaining sheet portions.

9. A method of making a printing plate, consisting in cementing a sheet of pyroxylin material to a base member, cutting and peeling away portions of the sheet and sloping the margins of the remaining portions, softening said sloping margins with a solvent and smoothing the softened slopes.

10. A printing plate comprising a metal base member having a pitted surface, and a sheet coating of pyroxylin material having a rough surface, the sheet coating being cemented to the base with its rough side outermost and said side having level variations and constituting the printing surface of the plate.

11. A printing plate comprising a base member, a sheet coating of pyroxylin material cemented thereto, certain portions of said coating being recessed to expose the plate, and a lacquer medium applied to the edges of the remaining portions of the coating, the surface of said portions being irregular and capable of producing tonal variations in a print impressed by said plate.

12. A method of producing a printing plate, consisting in cementing to a base member a sheet of material, softening the exposed side of the sheet, and brushing the softened surface to form portions of the sheet with acetone to form suriace irregularities capable oi producing tonal variations in a print impressed by the printing plate.

14. A printirg plate comprising a base member and a plasma, sheet coating cemented thereto,

said coating being recessed to provide raised areas constituting the printing surfaces oi the plate and intervening depressions constituting the voids of the printing plate, and said printing surfaces having irregular level variations capable of producing corresponding tonal variations in a print impressed thereby. as distinguished from the printing variations produced by said depress sions or voids.

BARNARD J. LEWIS. 

